After market lenses for Yi 4k + action cameras.

I have a Yi 4k + action camera and I am about to travel abroad on vacation. I want to replace the standard lens that I think is 150 degrees POV since it has too much distortion.

Pixaero manufactures lenses for after market. But I'm having a hard time deciding which lens to buy. The website strongly suggests a 3.4mm lens that is equivalent to a 18mm focal light. That for me still sounds very broad. Although the lens claims less than 0.5% distortion.

I thought that your 6mm lens would be better, since it has a focal length of 35mm.

I know that the first lens is good for the landscape and the wide scene. But what about distant and closer means? The other problem is that the 3.4 mm lens is 30% more expensive.

I used the standard lens to try to take a picture in an air show, but the plane was no bigger than the points in the air. Will the 6mm give decent video in all ranges? The 3.4mm really has such and advantage.